U.S. Pat. No. 5,026,554 to Bartizal et al discloses a method of inhibiting fungal growth using a non-phosphorus containing inhibitor of squalene synthetase having the structure ##STR1## wherein Z.sub.1, Z.sub.2 and Z.sub.3 are each independently selected from:
(a) H;
(b) C.sub.1-3 alkyl;
(c) C.sub.1-3 alkyl substituted with a member of the group consisting of:
(i) phenyl, PA1 (ii) phenyl substituted with methyl, ethoxy, halogen (Cl, Br, F, I) or hydroxy; or
a pharmaceutically acceptable salt of a compound of the above formula.
Squalene synthetase is a microsomal enzyme which catalyzes the reductive dimerization of two molecules of farnesyl pyrophosphate (FPP) in the presence of nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH) to form squalene (Poulter, C. D.; Rilling, H. C., in "Biosynthesis of Isoprenoid Compounds," Vol. I, Chapter 8, pp. 413-441, J. Wiley and Sons, 1981, and references therein). This enzyme is the first committed step of the de novo cholesterol biosynthetic pathway.
Squalene synthetase inhibitors which block the action of squalene synthetase (after the formation of farnesyl pyrophosphate) are disclosed in U.S. Pat. Nos. 4,871,721 and 5,025,003, U.S. application Ser. No. 501,204, filed Mar. 29, 1990, U.S. application Ser. No. 699,429, filed May 13, 1991, and U.S. application Ser. No. 07/967,904, filed Oct. 28, 1992, now abandoned which discloses .alpha.-phosphonosulfonate squalene synthetase inhibitors.